1. Technical Field
The disclosure relates in general to a method for manufacturing a semiconductor device, and more particularly to the method for manufacturing a semiconductor device with deposition of a nitride hard mask (HM) film to protect a cell gate from damage in the subsequent manufacturing procedures.
2. Description of the Related Art
Size of semiconductor device applied in the electronic product has been decreased for these years. Reduction of feature size, increase of resolution, improvements of the rate, the efficiency, the density and the cost per integrated circuit unit are the important goals in the semiconductor technology. The electrical properties of the device have to be maintained even improved with the decrease of the size, to meet the requirements of the commercial products in applications. If the layers and/or components of the device are damaged, it would have considerable effects on the electrical properties.
For high resolution requirement, the thickness of photoresist trend to thin down. An electronic product (such as flash product) may have two devices at different areas of the substrate, and the devices have different step height profiles on the substrate. In the manufacturing method, the upper polysilicon layer of a device such as flash gate could be damaged during etching process. Conventionally, two layers such as the first bottom anti-reflective coating (BARC) and the second BARC and the lithography processes thereof are applied above the polysilicon layer in the manufacturing method for preventing the upper poly from being damaged during etching process. Typically, the first BARC is remained to protect the poly in an non-pure logic area (flash/memory) on the substrate, and the second BARC is deposited on the 1st BARC. However, this would cause adhesion issue between the first BARC and second BARC. Also, the stack of the first BARC and second BARC may be too high to be remained in a stable condition, and would be collapsed easily. Those problems would have considerable effects on the electrical properties of the devices of the electronic product in application.